Swivel lock by itself is fine on four wheeled objects because you can lock the casters at different angles so no one caster can roll without making the others s

Swivel lock by itself is fine on four wheeled objects because you can lock the casters at different angles so no one caster can roll without making the others slide. It's rare to find casters that are swivel lock but not wheel lock since it's easy to make a mechanism that does both.